Remove "const" from pointer parameters.

This matches the types of those pointer parameters in their declarations
in common/av1_config.h. Visual Studio allows the constness of parameters
to differ between declaration and definition in C++, but not in C.

BUG=aomedia:2137

Change-Id: I11e4781056678aa10091534532665f57d14c003a

common/av1_config.c

diff --git a/common/av1_config.c b/common/av1_config.c
index 08ddc59..e8decf7 100644
--- a/common/av1_config.c
+++ b/common/av1_config.c
@@ -383,8 +383,8 @@
   return 0;
 }
 
-int get_av1config_from_obu(const uint8_t *const buffer, size_t length,
-                           int is_annexb, Av1Config *config) {
+int get_av1config_from_obu(const uint8_t *buffer, size_t length, int is_annexb,
+                           Av1Config *config) {
   if (!buffer || length == 0 || !config) {
     return -1;
   }
@@ -409,7 +409,7 @@
                                sequence_header_length, config);
 }
 
-int read_av1config(const uint8_t *const buffer, size_t buffer_length,
+int read_av1config(const uint8_t *buffer, size_t buffer_length,
                    size_t *bytes_read, Av1Config *config) {
   if (!buffer || buffer_length < kAv1cSize || !bytes_read || !config) return -1;
 
@@ -471,7 +471,7 @@
   return 0;
 }
 
-int write_av1config(const Av1Config *const config, size_t capacity,
+int write_av1config(const Av1Config *config, size_t capacity,
                     size_t *bytes_written, uint8_t *buffer) {
   if (!config || !buffer || capacity < kAv1cSize || !bytes_written) return -1;